react-native/Libraries/Animated/__tests__/Interpolation-test.js

/**
 * Copyright (c) 2015-present, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 */
'use strict';

jest
  .dontMock('Interpolation')
  .dontMock('Easing');

var Interpolation = require('Interpolation');
var Easing = require('Easing');

describe('Interpolation', () => {
  it('should work with defaults', () => {
    var interpolation = Interpolation.create({
      inputRange: [0, 1],
      outputRange: [0, 1],
    });

    expect(interpolation(0)).toBe(0);
    expect(interpolation(0.5)).toBe(0.5);
    expect(interpolation(0.8)).toBe(0.8);
    expect(interpolation(1)).toBe(1);
  });

  it('should work with output range', () => {
    var interpolation = Interpolation.create({
      inputRange: [0, 1],
      outputRange: [100, 200],
    });

    expect(interpolation(0)).toBe(100);
    expect(interpolation(0.5)).toBe(150);
    expect(interpolation(0.8)).toBe(180);
    expect(interpolation(1)).toBe(200);
  });

  it('should work with input range', () => {
    var interpolation = Interpolation.create({
      inputRange: [100, 200],
      outputRange: [0, 1],
    });

    expect(interpolation(100)).toBe(0);
    expect(interpolation(150)).toBe(0.5);
    expect(interpolation(180)).toBe(0.8);
    expect(interpolation(200)).toBe(1);
  });

  it('should throw for non monotonic input ranges', () => {
    expect(() => Interpolation.create({
      inputRange: [0, 2, 1],
      outputRange: [0, 1, 2],
    })).toThrow();

    expect(() => Interpolation.create({
      inputRange: [0, 1, 2],
      outputRange: [0, 3, 1],
    })).not.toThrow();
  });

  it('should work with empty input range', () => {
    var interpolation = Interpolation.create({
      inputRange: [0, 10, 10],
      outputRange: [1, 2, 3],
      extrapolate: 'extend',
    });

    expect(interpolation(0)).toBe(1);
    expect(interpolation(5)).toBe(1.5);
    expect(interpolation(10)).toBe(2);
    expect(interpolation(10.1)).toBe(3);
    expect(interpolation(15)).toBe(3);
  });

  it('should work with empty output range', () => {
    var interpolation = Interpolation.create({
      inputRange: [1, 2, 3],
      outputRange: [0, 10, 10],
      extrapolate: 'extend',
    });

    expect(interpolation(0)).toBe(-10);
    expect(interpolation(1.5)).toBe(5);
    expect(interpolation(2)).toBe(10);
    expect(interpolation(2.5)).toBe(10);
    expect(interpolation(3)).toBe(10);
    expect(interpolation(4)).toBe(10);
  });

  it('should work with easing', () => {
    var interpolation = Interpolation.create({
      inputRange: [0, 1],
      outputRange: [0, 1],
      easing: Easing.quad,
    });

    expect(interpolation(0)).toBe(0);
    expect(interpolation(0.5)).toBe(0.25);
    expect(interpolation(0.9)).toBe(0.81);
    expect(interpolation(1)).toBe(1);
  });

  it('should work with extrapolate', () => {
    var interpolation = Interpolation.create({
      inputRange: [0, 1],
      outputRange: [0, 1],
      extrapolate: 'extend',
      easing: Easing.quad,
    });

    expect(interpolation(-2)).toBe(4);
    expect(interpolation(2)).toBe(4);

    interpolation = Interpolation.create({
      inputRange: [0, 1],
      outputRange: [0, 1],
      extrapolate: 'clamp',
      easing: Easing.quad,
    });

    expect(interpolation(-2)).toBe(0);
    expect(interpolation(2)).toBe(1);

    interpolation = Interpolation.create({
      inputRange: [0, 1],
      outputRange: [0, 1],
      extrapolate: 'identity',
      easing: Easing.quad,
    });

    expect(interpolation(-2)).toBe(-2);
    expect(interpolation(2)).toBe(2);
  });

  it('should work with keyframes with extrapolate', () => {
    var interpolation = Interpolation.create({
      inputRange: [0, 10, 100, 1000],
      outputRange: [0, 5, 50, 500],
      extrapolate: true,
    });

    expect(interpolation(-5)).toBe(-2.5);
    expect(interpolation(0)).toBe(0);
    expect(interpolation(5)).toBe(2.5);
    expect(interpolation(10)).toBe(5);
    expect(interpolation(50)).toBe(25);
    expect(interpolation(100)).toBe(50);
    expect(interpolation(500)).toBe(250);
    expect(interpolation(1000)).toBe(500);
    expect(interpolation(2000)).toBe(1000);
  });

  it('should work with keyframes without extrapolate', () => {
    var interpolation = Interpolation.create({
      inputRange: [0, 1, 2],
      outputRange: [0.2, 1, 0.2],
      extrapolate: 'clamp',
    });

    expect(interpolation(5)).toBeCloseTo(0.2);
  });

  it('should throw for an infinite input range', () => {
    expect(() => Interpolation.create({
      inputRange: [-Infinity, Infinity],
      outputRange: [0, 1],
    })).toThrow();

    expect(() => Interpolation.create({
      inputRange: [-Infinity, 0, Infinity],
      outputRange: [1, 2, 3],
    })).not.toThrow();
  });

  it('should work with negative infinite', () => {
    var interpolation = Interpolation.create({
      inputRange: [-Infinity, 0],
      outputRange: [-Infinity, 0],
      easing: Easing.quad,
      extrapolate: 'identity',
    });

    expect(interpolation(-Infinity)).toBe(-Infinity);
    expect(interpolation(-100)).toBeCloseTo(-10000);
    expect(interpolation(-10)).toBeCloseTo(-100);
    expect(interpolation(0)).toBeCloseTo(0);
    expect(interpolation(1)).toBeCloseTo(1);
    expect(interpolation(100)).toBeCloseTo(100);
  });

  it('should work with positive infinite', () => {
    var interpolation = Interpolation.create({
      inputRange: [5, Infinity],
      outputRange: [5, Infinity],
      easing: Easing.quad,
      extrapolate: 'identity',
    });

    expect(interpolation(-100)).toBeCloseTo(-100);
    expect(interpolation(-10)).toBeCloseTo(-10);
    expect(interpolation(0)).toBeCloseTo(0);
    expect(interpolation(5)).toBeCloseTo(5);
    expect(interpolation(6)).toBeCloseTo(5 + 1);
    expect(interpolation(10)).toBeCloseTo(5 + 25);
    expect(interpolation(100)).toBeCloseTo(5 + (95 * 95));
    expect(interpolation(Infinity)).toBe(Infinity);
  });

  it('should work with output ranges as string', () => {
    var interpolation = Interpolation.create({
      inputRange: [0, 1],
      outputRange: ['rgba(0, 100, 200, 0)', 'rgba(50, 150, 250, 0.5)'],
    });

    expect(interpolation(0)).toBe('rgba(0, 100, 200, 0)');
    expect(interpolation(0.5)).toBe('rgba(25, 125, 225, 0.25)');
    expect(interpolation(1)).toBe('rgba(50, 150, 250, 0.5)');
  });

  it('should work with negative and decimal values in string ranges', () => {
    var interpolation = Interpolation.create({
      inputRange: [0, 1],
      outputRange: ['-100.5deg', '100deg'],
    });

    expect(interpolation(0)).toBe('-100.5deg');
    expect(interpolation(0.5)).toBe('-0.25deg');
    expect(interpolation(1)).toBe('100deg');
  });

  it('should crash when chaining an interpolation that returns a string', () => {
    var interpolation = Interpolation.create({
      inputRange: [0, 1],
      outputRange: [0, 1],
    });
    expect(() => { interpolation('45rad'); }).toThrow();
  });

  it('should crash when defining output range with different pattern', () => {
    expect(() => Interpolation.create({
      inputRange: [0, 1],
      outputRange: ['rgba(0, 100, 200, 0)', 'rgb(50, 150, 250)'],
    })).toThrow();

    expect(() => Interpolation.create({
      inputRange: [0, 1],
      outputRange: ['20deg', '30rad'],
    })).toThrow();
  });
});